1. Field of the Invention
The present invention relates generally to a clutch mechanism in the driving train of a washing machine agitator.
2. Description of the Prior Art
It is recognized that dual action agitators in washing machines provide improved washing action and facilitate uniform cleaning of larger loads. Such dual action agitators generally include a lower radially vaned agitator portion that moves in an oscillatory fashion and an upper agitator portion that moves in a separate path from the lower portion. The motion of the upper portion provides rollover of the clothes load for more uniform cleaning during a washing cycle.
A method and apparatus for dual action agitation in a washing machine are disclosed in U.S. Pat. Nos. 3,987,508 and 3,987,651 in which an auger-like vane driven by a one way clutch provides rollover of clothes toward an oscillating main agitator element. A clutch for use in such dual action agitator is disclosed in U.S. Pat. No. 4,164,130 that includes a pair of clutch shoes which are thrust outward by a cam surface to an engagement surface of an auger on a first oscillation motion and which are engaged at a capture surface and drawn inward on a reverse oscillation motion. The specification reveals that should the clutch parts become wet they may stick and cause the clutch not to work.
A ratchet-type clutch for dual action agitators is disclosed in U.S. Pat. No. 4,155,228 that includes upwardly and downwardly directed teeth for mutual engagement, each tooth having a slip surface and a drive surface. A one way clutch is also disclosed in U.S. Pat. No. 3,987,652 in which a plurality of pawls engage a series of teeth on a ratchet ring.
Dual action agitators are also known in which vertical motion is imparted to an upper agitator barrel. For instance, in U.S. Pat. No. 3,678,714 a cam follower roller moving over high and low points on a cam surface drives a secondary agitator vertically. In U.S. Pat. No. 4,520,638, a pin riding in a recessed parallelogram provides vertical movement, while in U.S. Pat. No. 4,452,054, driving lugs engage spiral drive surfaces for vertical reciprocating motion of an upper portion of an agitator.